Farmall H 6 volt coil problems

I'm not getting spark out of my coil. Is there a way to make sure its bad. I don't want to buy a new one if I don't need to.

Thanks

Mark

Mark, there are zillions of posts on this subject in the IH Forum archives. search for any keyword like ignition problem, starting H , coils, etc etc.
I find the classic view is easiest to work with for searches. Look for answers from the likes of JimN, John T, BobM, etc.
Dell

First off check to make sure you have power in the ignition side of the coil. If you do then check yours points and make sure they are clean and you get a spark from them when you open and close them by hand. Bad points can cause that same problem or even a bad condenser

Mark, a simple ohm meter continuity test can "make sure its bad" as you asked butttttttttt it cant tell you if its good !!!!!!!!! i.e. just cuz it passes the simple low voltage ohm continuity tests dont mean it wont still break down at high voltage and under temperatire conditions.

The primary as measured between its lil + and - terminals would be around 1.25 to under 2 ohms on a 6 volt coil BUT if its an open (near infinity ohms) circuit its BAD for sure.....

Use a test lamp or voltmeter to make sure theres hot battery voltage on the coils input (NOT distributor side) when the ignition is turned on cuz shes never gonna fire otherwise......

Then place a 6/12 test lamp on the coils other (TO distributor) side (other lead to frame ground) and it should lite up when the points open but go dead off when they are closed...

Remove the cap to make sure the points are gapped correct and open n fully close as the distributor shaft rotates......

A COMMON problem is the points are burned or pitted badly so check that and clean/file/buff them as necessary and check the gap n try again n see if she fires?????

To isolate if its a cap or rotor problem ONLY,,,,,, remove the coil wire from the top of distributor (leave coil end intact) n place that bare end 1/8 from tractor steel n turn on ignition n crank engione n see if a spark jumps that coil wire gap ??? If so but NOT out any plug wires once cap is replaced, its a cap or rotor or plug wire type problem

CHECK THE POINTS FOR GAP AND CLEAN/FILE N TRY THEM OR REPALCE IF BAD BURNED OR PITTED THAT MAY BE ALL THE PROBLEM

John T

Open the distributor cap
Put a thin piece of plastic between the points to keep them open.
Pull the coil wire out of the center of the distributor cap
tape it with any tape so the metal of the wire is 1/8 to 3/16" away from a ground (engine block)
Turn on the ignition
Use a plastic handled screw driver to short the terminal on the side of the distributor to the distributor case.
As this connection is made and broken, the coil should make a nice blue spark to the block.
If yes, it is a good coil.
If no see if the screw driver itself is making a tiny spark.
if no, disconnect the wire from that distributor terminal and (holding the insulation) touch it to ground. If nothing sparks at all, (the little wire, or spark wire, check to make sure there is voltage to the Switch side of the coil. If there is 6v there, scrap the coil. If no 6 volts, run a temporary wire from the battery non ground terminalto the coil switch side and repeat the experiments.
If nothing, junk the coil.
If it works now the switch or wires are open and not feeding volts to the coil. JimN

You got fire to it?